Mobile communication devices have become increasingly common in current society. The prevalence of these mobile communication devices is driven in part by the many functions that are now enabled on such devices. Increased processing capabilities in such devices means that mobile communication devices have evolved from being pure communication tools into sophisticated mobile multimedia centers that enable enhanced user experiences.
The redefined user experience requires higher data rate offered by wireless communication technologies, such as long-term evolution (LTE). To achieve the higher data rate in mobile communication devices, sophisticated power amplifiers (PAs) may be employed to increase output power of radio frequency (RF) signals (e.g., maintaining sufficient energy per bit) communicated by mobile communication devices. However, the increased output power of RF signals can lead to increased power consumption and thermal dissipation in mobile communication devices, thus compromising overall performance and user experiences.
Envelope tracking is a power management technology designed to improve efficiency levels of PAs to help reduce power consumption and thermal dissipation in mobile communication devices. As the name suggests, envelope tracking employs a system that keeps track of the amplitude envelope of the RF signals communicated by mobile communication devices. The envelope tracking system constantly adjusts supply voltage applied to the PAs to ensure that the PAs are operating at a higher efficiency for a given instantaneous output power requirement of the RF signals. In addition, it can help to further improve efficiency of the PAs by minimizing electrical currents sourced from the PAs.